Add day one

.gitignore

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+*.txt
+

day_1.js

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+const fs = require("fs");
+
+// PART 1
+{
+	const result = fs.readFileSync("day_1.txt")
+		.toString()
+		.split("\n")
+		.map(line => line.split("").find(isFinite) + line.split("").findLast(isFinite))
+		.map(Number)
+		.filter(isFinite)
+		.reduce((acc, val) => acc + val, 0);
+
+	console.log(result);
+}
+
+// PART 2
+const digits = ["one", "two", "three", "four", "five", "six", "seven", "eight", "nine"];
+
+function isNumber(char, i, arr) {
+	return isFinite(char) || digits.some(digit => arr.slice(i).join("").startsWith(digit));
+}
+
+function getNumber(line, index) {
+	if (isFinite(line.charAt(index)))
+		return line.charAt(index);
+
+	for (let i = 0; i < digits.length; i++)
+		if (line.slice(index).startsWith(digits[i])) return (i + 1).toString();
+}
+
+{
+
+	const result = fs.readFileSync("day_1.txt")
+		.toString()
+		.split("\n")
+		.map(line => getNumber(line, line.split("").findIndex(isNumber)) + getNumber(line, line.split("").findLastIndex(isNumber)))
+		.map(Number)
+		.filter(isFinite)
+		.reduce((acc, val) => acc + val, 0);
+
+	console.log(result);
+}
+